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Merge tag 'nfsd-5.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
[mirror_ubuntu-jammy-kernel.git] / net / ipv6 / udp.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * UDP over IPv6
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 *
9 * Based on linux/ipv4/udp.c
10 *
11 * Fixes:
12 * Hideaki YOSHIFUJI : sin6_scope_id support
13 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
14 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
15 * a single port at the same time.
16 * Kazunori MIYAZAWA @USAGI: change process style to use ip6_append_data
17 * YOSHIFUJI Hideaki @USAGI: convert /proc/net/udp6 to seq_file.
18 */
19
20 #include <linux/errno.h>
21 #include <linux/types.h>
22 #include <linux/socket.h>
23 #include <linux/sockios.h>
24 #include <linux/net.h>
25 #include <linux/in6.h>
26 #include <linux/netdevice.h>
27 #include <linux/if_arp.h>
28 #include <linux/ipv6.h>
29 #include <linux/icmpv6.h>
30 #include <linux/init.h>
31 #include <linux/module.h>
32 #include <linux/skbuff.h>
33 #include <linux/slab.h>
34 #include <linux/uaccess.h>
35 #include <linux/indirect_call_wrapper.h>
36
37 #include <net/addrconf.h>
38 #include <net/ndisc.h>
39 #include <net/protocol.h>
40 #include <net/transp_v6.h>
41 #include <net/ip6_route.h>
42 #include <net/raw.h>
43 #include <net/tcp_states.h>
44 #include <net/ip6_checksum.h>
45 #include <net/ip6_tunnel.h>
46 #include <net/xfrm.h>
47 #include <net/inet_hashtables.h>
48 #include <net/inet6_hashtables.h>
49 #include <net/busy_poll.h>
50 #include <net/sock_reuseport.h>
51
52 #include <linux/proc_fs.h>
53 #include <linux/seq_file.h>
54 #include <trace/events/skb.h>
55 #include "udp_impl.h"
56
57 static u32 udp6_ehashfn(const struct net *net,
58 const struct in6_addr *laddr,
59 const u16 lport,
60 const struct in6_addr *faddr,
61 const __be16 fport)
62 {
63 static u32 udp6_ehash_secret __read_mostly;
64 static u32 udp_ipv6_hash_secret __read_mostly;
65
66 u32 lhash, fhash;
67
68 net_get_random_once(&udp6_ehash_secret,
69 sizeof(udp6_ehash_secret));
70 net_get_random_once(&udp_ipv6_hash_secret,
71 sizeof(udp_ipv6_hash_secret));
72
73 lhash = (__force u32)laddr->s6_addr32[3];
74 fhash = __ipv6_addr_jhash(faddr, udp_ipv6_hash_secret);
75
76 return __inet6_ehashfn(lhash, lport, fhash, fport,
77 udp_ipv6_hash_secret + net_hash_mix(net));
78 }
79
80 int udp_v6_get_port(struct sock *sk, unsigned short snum)
81 {
82 unsigned int hash2_nulladdr =
83 ipv6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
84 unsigned int hash2_partial =
85 ipv6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0);
86
87 /* precompute partial secondary hash */
88 udp_sk(sk)->udp_portaddr_hash = hash2_partial;
89 return udp_lib_get_port(sk, snum, hash2_nulladdr);
90 }
91
92 void udp_v6_rehash(struct sock *sk)
93 {
94 u16 new_hash = ipv6_portaddr_hash(sock_net(sk),
95 &sk->sk_v6_rcv_saddr,
96 inet_sk(sk)->inet_num);
97
98 udp_lib_rehash(sk, new_hash);
99 }
100
101 static int compute_score(struct sock *sk, struct net *net,
102 const struct in6_addr *saddr, __be16 sport,
103 const struct in6_addr *daddr, unsigned short hnum,
104 int dif, int sdif)
105 {
106 int score;
107 struct inet_sock *inet;
108 bool dev_match;
109
110 if (!net_eq(sock_net(sk), net) ||
111 udp_sk(sk)->udp_port_hash != hnum ||
112 sk->sk_family != PF_INET6)
113 return -1;
114
115 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
116 return -1;
117
118 score = 0;
119 inet = inet_sk(sk);
120
121 if (inet->inet_dport) {
122 if (inet->inet_dport != sport)
123 return -1;
124 score++;
125 }
126
127 if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
128 if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr))
129 return -1;
130 score++;
131 }
132
133 dev_match = udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif);
134 if (!dev_match)
135 return -1;
136 if (sk->sk_bound_dev_if)
137 score++;
138
139 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
140 score++;
141
142 return score;
143 }
144
145 static struct sock *lookup_reuseport(struct net *net, struct sock *sk,
146 struct sk_buff *skb,
147 const struct in6_addr *saddr,
148 __be16 sport,
149 const struct in6_addr *daddr,
150 unsigned int hnum)
151 {
152 struct sock *reuse_sk = NULL;
153 u32 hash;
154
155 if (sk->sk_reuseport && sk->sk_state != TCP_ESTABLISHED) {
156 hash = udp6_ehashfn(net, daddr, hnum, saddr, sport);
157 reuse_sk = reuseport_select_sock(sk, hash, skb,
158 sizeof(struct udphdr));
159 }
160 return reuse_sk;
161 }
162
163 /* called with rcu_read_lock() */
164 static struct sock *udp6_lib_lookup2(struct net *net,
165 const struct in6_addr *saddr, __be16 sport,
166 const struct in6_addr *daddr, unsigned int hnum,
167 int dif, int sdif, struct udp_hslot *hslot2,
168 struct sk_buff *skb)
169 {
170 struct sock *sk, *result;
171 int score, badness;
172
173 result = NULL;
174 badness = -1;
175 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
176 score = compute_score(sk, net, saddr, sport,
177 daddr, hnum, dif, sdif);
178 if (score > badness) {
179 result = lookup_reuseport(net, sk, skb,
180 saddr, sport, daddr, hnum);
181 /* Fall back to scoring if group has connections */
182 if (result && !reuseport_has_conns(sk, false))
183 return result;
184
185 result = result ? : sk;
186 badness = score;
187 }
188 }
189 return result;
190 }
191
192 static inline struct sock *udp6_lookup_run_bpf(struct net *net,
193 struct udp_table *udptable,
194 struct sk_buff *skb,
195 const struct in6_addr *saddr,
196 __be16 sport,
197 const struct in6_addr *daddr,
198 u16 hnum)
199 {
200 struct sock *sk, *reuse_sk;
201 bool no_reuseport;
202
203 if (udptable != &udp_table)
204 return NULL; /* only UDP is supported */
205
206 no_reuseport = bpf_sk_lookup_run_v6(net, IPPROTO_UDP,
207 saddr, sport, daddr, hnum, &sk);
208 if (no_reuseport || IS_ERR_OR_NULL(sk))
209 return sk;
210
211 reuse_sk = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum);
212 if (reuse_sk)
213 sk = reuse_sk;
214 return sk;
215 }
216
217 /* rcu_read_lock() must be held */
218 struct sock *__udp6_lib_lookup(struct net *net,
219 const struct in6_addr *saddr, __be16 sport,
220 const struct in6_addr *daddr, __be16 dport,
221 int dif, int sdif, struct udp_table *udptable,
222 struct sk_buff *skb)
223 {
224 unsigned short hnum = ntohs(dport);
225 unsigned int hash2, slot2;
226 struct udp_hslot *hslot2;
227 struct sock *result, *sk;
228
229 hash2 = ipv6_portaddr_hash(net, daddr, hnum);
230 slot2 = hash2 & udptable->mask;
231 hslot2 = &udptable->hash2[slot2];
232
233 /* Lookup connected or non-wildcard sockets */
234 result = udp6_lib_lookup2(net, saddr, sport,
235 daddr, hnum, dif, sdif,
236 hslot2, skb);
237 if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED)
238 goto done;
239
240 /* Lookup redirect from BPF */
241 if (static_branch_unlikely(&bpf_sk_lookup_enabled)) {
242 sk = udp6_lookup_run_bpf(net, udptable, skb,
243 saddr, sport, daddr, hnum);
244 if (sk) {
245 result = sk;
246 goto done;
247 }
248 }
249
250 /* Got non-wildcard socket or error on first lookup */
251 if (result)
252 goto done;
253
254 /* Lookup wildcard sockets */
255 hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
256 slot2 = hash2 & udptable->mask;
257 hslot2 = &udptable->hash2[slot2];
258
259 result = udp6_lib_lookup2(net, saddr, sport,
260 &in6addr_any, hnum, dif, sdif,
261 hslot2, skb);
262 done:
263 if (IS_ERR(result))
264 return NULL;
265 return result;
266 }
267 EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
268
269 static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
270 __be16 sport, __be16 dport,
271 struct udp_table *udptable)
272 {
273 const struct ipv6hdr *iph = ipv6_hdr(skb);
274
275 return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
276 &iph->daddr, dport, inet6_iif(skb),
277 inet6_sdif(skb), udptable, skb);
278 }
279
280 struct sock *udp6_lib_lookup_skb(const struct sk_buff *skb,
281 __be16 sport, __be16 dport)
282 {
283 const struct ipv6hdr *iph = ipv6_hdr(skb);
284
285 return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
286 &iph->daddr, dport, inet6_iif(skb),
287 inet6_sdif(skb), &udp_table, NULL);
288 }
289
290 /* Must be called under rcu_read_lock().
291 * Does increment socket refcount.
292 */
293 #if IS_ENABLED(CONFIG_NF_TPROXY_IPV6) || IS_ENABLED(CONFIG_NF_SOCKET_IPV6)
294 struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
295 const struct in6_addr *daddr, __be16 dport, int dif)
296 {
297 struct sock *sk;
298
299 sk = __udp6_lib_lookup(net, saddr, sport, daddr, dport,
300 dif, 0, &udp_table, NULL);
301 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
302 sk = NULL;
303 return sk;
304 }
305 EXPORT_SYMBOL_GPL(udp6_lib_lookup);
306 #endif
307
308 /* do not use the scratch area len for jumbogram: their length execeeds the
309 * scratch area space; note that the IP6CB flags is still in the first
310 * cacheline, so checking for jumbograms is cheap
311 */
312 static int udp6_skb_len(struct sk_buff *skb)
313 {
314 return unlikely(inet6_is_jumbogram(skb)) ? skb->len : udp_skb_len(skb);
315 }
316
317 /*
318 * This should be easy, if there is something there we
319 * return it, otherwise we block.
320 */
321
322 int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
323 int noblock, int flags, int *addr_len)
324 {
325 struct ipv6_pinfo *np = inet6_sk(sk);
326 struct inet_sock *inet = inet_sk(sk);
327 struct sk_buff *skb;
328 unsigned int ulen, copied;
329 int off, err, peeking = flags & MSG_PEEK;
330 int is_udplite = IS_UDPLITE(sk);
331 struct udp_mib __percpu *mib;
332 bool checksum_valid = false;
333 int is_udp4;
334
335 if (flags & MSG_ERRQUEUE)
336 return ipv6_recv_error(sk, msg, len, addr_len);
337
338 if (np->rxpmtu && np->rxopt.bits.rxpmtu)
339 return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
340
341 try_again:
342 off = sk_peek_offset(sk, flags);
343 skb = __skb_recv_udp(sk, flags, noblock, &off, &err);
344 if (!skb)
345 return err;
346
347 ulen = udp6_skb_len(skb);
348 copied = len;
349 if (copied > ulen - off)
350 copied = ulen - off;
351 else if (copied < ulen)
352 msg->msg_flags |= MSG_TRUNC;
353
354 is_udp4 = (skb->protocol == htons(ETH_P_IP));
355 mib = __UDPX_MIB(sk, is_udp4);
356
357 /*
358 * If checksum is needed at all, try to do it while copying the
359 * data. If the data is truncated, or if we only want a partial
360 * coverage checksum (UDP-Lite), do it before the copy.
361 */
362
363 if (copied < ulen || peeking ||
364 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
365 checksum_valid = udp_skb_csum_unnecessary(skb) ||
366 !__udp_lib_checksum_complete(skb);
367 if (!checksum_valid)
368 goto csum_copy_err;
369 }
370
371 if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
372 if (udp_skb_is_linear(skb))
373 err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
374 else
375 err = skb_copy_datagram_msg(skb, off, msg, copied);
376 } else {
377 err = skb_copy_and_csum_datagram_msg(skb, off, msg);
378 if (err == -EINVAL)
379 goto csum_copy_err;
380 }
381 if (unlikely(err)) {
382 if (!peeking) {
383 atomic_inc(&sk->sk_drops);
384 SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
385 }
386 kfree_skb(skb);
387 return err;
388 }
389 if (!peeking)
390 SNMP_INC_STATS(mib, UDP_MIB_INDATAGRAMS);
391
392 sock_recv_ts_and_drops(msg, sk, skb);
393
394 /* Copy the address. */
395 if (msg->msg_name) {
396 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
397 sin6->sin6_family = AF_INET6;
398 sin6->sin6_port = udp_hdr(skb)->source;
399 sin6->sin6_flowinfo = 0;
400
401 if (is_udp4) {
402 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
403 &sin6->sin6_addr);
404 sin6->sin6_scope_id = 0;
405 } else {
406 sin6->sin6_addr = ipv6_hdr(skb)->saddr;
407 sin6->sin6_scope_id =
408 ipv6_iface_scope_id(&sin6->sin6_addr,
409 inet6_iif(skb));
410 }
411 *addr_len = sizeof(*sin6);
412
413 BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk,
414 (struct sockaddr *)sin6);
415 }
416
417 if (udp_sk(sk)->gro_enabled)
418 udp_cmsg_recv(msg, sk, skb);
419
420 if (np->rxopt.all)
421 ip6_datagram_recv_common_ctl(sk, msg, skb);
422
423 if (is_udp4) {
424 if (inet->cmsg_flags)
425 ip_cmsg_recv_offset(msg, sk, skb,
426 sizeof(struct udphdr), off);
427 } else {
428 if (np->rxopt.all)
429 ip6_datagram_recv_specific_ctl(sk, msg, skb);
430 }
431
432 err = copied;
433 if (flags & MSG_TRUNC)
434 err = ulen;
435
436 skb_consume_udp(sk, skb, peeking ? -err : err);
437 return err;
438
439 csum_copy_err:
440 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
441 udp_skb_destructor)) {
442 SNMP_INC_STATS(mib, UDP_MIB_CSUMERRORS);
443 SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
444 }
445 kfree_skb(skb);
446
447 /* starting over for a new packet, but check if we need to yield */
448 cond_resched();
449 msg->msg_flags &= ~MSG_TRUNC;
450 goto try_again;
451 }
452
453 DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
454 void udpv6_encap_enable(void)
455 {
456 static_branch_inc(&udpv6_encap_needed_key);
457 }
458 EXPORT_SYMBOL(udpv6_encap_enable);
459
460 /* Handler for tunnels with arbitrary destination ports: no socket lookup, go
461 * through error handlers in encapsulations looking for a match.
462 */
463 static int __udp6_lib_err_encap_no_sk(struct sk_buff *skb,
464 struct inet6_skb_parm *opt,
465 u8 type, u8 code, int offset, __be32 info)
466 {
467 int i;
468
469 for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) {
470 int (*handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
471 u8 type, u8 code, int offset, __be32 info);
472 const struct ip6_tnl_encap_ops *encap;
473
474 encap = rcu_dereference(ip6tun_encaps[i]);
475 if (!encap)
476 continue;
477 handler = encap->err_handler;
478 if (handler && !handler(skb, opt, type, code, offset, info))
479 return 0;
480 }
481
482 return -ENOENT;
483 }
484
485 /* Try to match ICMP errors to UDP tunnels by looking up a socket without
486 * reversing source and destination port: this will match tunnels that force the
487 * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that
488 * lwtunnels might actually break this assumption by being configured with
489 * different destination ports on endpoints, in this case we won't be able to
490 * trace ICMP messages back to them.
491 *
492 * If this doesn't match any socket, probe tunnels with arbitrary destination
493 * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port
494 * we've sent packets to won't necessarily match the local destination port.
495 *
496 * Then ask the tunnel implementation to match the error against a valid
497 * association.
498 *
499 * Return an error if we can't find a match, the socket if we need further
500 * processing, zero otherwise.
501 */
502 static struct sock *__udp6_lib_err_encap(struct net *net,
503 const struct ipv6hdr *hdr, int offset,
504 struct udphdr *uh,
505 struct udp_table *udptable,
506 struct sock *sk,
507 struct sk_buff *skb,
508 struct inet6_skb_parm *opt,
509 u8 type, u8 code, __be32 info)
510 {
511 int (*lookup)(struct sock *sk, struct sk_buff *skb);
512 int network_offset, transport_offset;
513 struct udp_sock *up;
514
515 network_offset = skb_network_offset(skb);
516 transport_offset = skb_transport_offset(skb);
517
518 /* Network header needs to point to the outer IPv6 header inside ICMP */
519 skb_reset_network_header(skb);
520
521 /* Transport header needs to point to the UDP header */
522 skb_set_transport_header(skb, offset);
523
524 if (sk) {
525 up = udp_sk(sk);
526
527 lookup = READ_ONCE(up->encap_err_lookup);
528 if (lookup && lookup(sk, skb))
529 sk = NULL;
530
531 goto out;
532 }
533
534 sk = __udp6_lib_lookup(net, &hdr->daddr, uh->source,
535 &hdr->saddr, uh->dest,
536 inet6_iif(skb), 0, udptable, skb);
537 if (sk) {
538 up = udp_sk(sk);
539
540 lookup = READ_ONCE(up->encap_err_lookup);
541 if (!lookup || lookup(sk, skb))
542 sk = NULL;
543 }
544
545 out:
546 if (!sk) {
547 sk = ERR_PTR(__udp6_lib_err_encap_no_sk(skb, opt, type, code,
548 offset, info));
549 }
550
551 skb_set_transport_header(skb, transport_offset);
552 skb_set_network_header(skb, network_offset);
553
554 return sk;
555 }
556
557 int __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
558 u8 type, u8 code, int offset, __be32 info,
559 struct udp_table *udptable)
560 {
561 struct ipv6_pinfo *np;
562 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
563 const struct in6_addr *saddr = &hdr->saddr;
564 const struct in6_addr *daddr = &hdr->daddr;
565 struct udphdr *uh = (struct udphdr *)(skb->data+offset);
566 bool tunnel = false;
567 struct sock *sk;
568 int harderr;
569 int err;
570 struct net *net = dev_net(skb->dev);
571
572 sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source,
573 inet6_iif(skb), inet6_sdif(skb), udptable, NULL);
574
575 if (!sk || udp_sk(sk)->encap_type) {
576 /* No socket for error: try tunnels before discarding */
577 if (static_branch_unlikely(&udpv6_encap_needed_key)) {
578 sk = __udp6_lib_err_encap(net, hdr, offset, uh,
579 udptable, sk, skb,
580 opt, type, code, info);
581 if (!sk)
582 return 0;
583 } else
584 sk = ERR_PTR(-ENOENT);
585
586 if (IS_ERR(sk)) {
587 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
588 ICMP6_MIB_INERRORS);
589 return PTR_ERR(sk);
590 }
591
592 tunnel = true;
593 }
594
595 harderr = icmpv6_err_convert(type, code, &err);
596 np = inet6_sk(sk);
597
598 if (type == ICMPV6_PKT_TOOBIG) {
599 if (!ip6_sk_accept_pmtu(sk))
600 goto out;
601 ip6_sk_update_pmtu(skb, sk, info);
602 if (np->pmtudisc != IPV6_PMTUDISC_DONT)
603 harderr = 1;
604 }
605 if (type == NDISC_REDIRECT) {
606 if (tunnel) {
607 ip6_redirect(skb, sock_net(sk), inet6_iif(skb),
608 sk->sk_mark, sk->sk_uid);
609 } else {
610 ip6_sk_redirect(skb, sk);
611 }
612 goto out;
613 }
614
615 /* Tunnels don't have an application socket: don't pass errors back */
616 if (tunnel)
617 goto out;
618
619 if (!np->recverr) {
620 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
621 goto out;
622 } else {
623 ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
624 }
625
626 sk->sk_err = err;
627 sk_error_report(sk);
628 out:
629 return 0;
630 }
631
632 static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
633 {
634 int rc;
635
636 if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
637 sock_rps_save_rxhash(sk, skb);
638 sk_mark_napi_id(sk, skb);
639 sk_incoming_cpu_update(sk);
640 } else {
641 sk_mark_napi_id_once(sk, skb);
642 }
643
644 rc = __udp_enqueue_schedule_skb(sk, skb);
645 if (rc < 0) {
646 int is_udplite = IS_UDPLITE(sk);
647
648 /* Note that an ENOMEM error is charged twice */
649 if (rc == -ENOMEM)
650 UDP6_INC_STATS(sock_net(sk),
651 UDP_MIB_RCVBUFERRORS, is_udplite);
652 else
653 UDP6_INC_STATS(sock_net(sk),
654 UDP_MIB_MEMERRORS, is_udplite);
655 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
656 kfree_skb(skb);
657 return -1;
658 }
659
660 return 0;
661 }
662
663 static __inline__ int udpv6_err(struct sk_buff *skb,
664 struct inet6_skb_parm *opt, u8 type,
665 u8 code, int offset, __be32 info)
666 {
667 return __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
668 }
669
670 static int udpv6_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
671 {
672 struct udp_sock *up = udp_sk(sk);
673 int is_udplite = IS_UDPLITE(sk);
674
675 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
676 goto drop;
677
678 if (static_branch_unlikely(&udpv6_encap_needed_key) && up->encap_type) {
679 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
680
681 /*
682 * This is an encapsulation socket so pass the skb to
683 * the socket's udp_encap_rcv() hook. Otherwise, just
684 * fall through and pass this up the UDP socket.
685 * up->encap_rcv() returns the following value:
686 * =0 if skb was successfully passed to the encap
687 * handler or was discarded by it.
688 * >0 if skb should be passed on to UDP.
689 * <0 if skb should be resubmitted as proto -N
690 */
691
692 /* if we're overly short, let UDP handle it */
693 encap_rcv = READ_ONCE(up->encap_rcv);
694 if (encap_rcv) {
695 int ret;
696
697 /* Verify checksum before giving to encap */
698 if (udp_lib_checksum_complete(skb))
699 goto csum_error;
700
701 ret = encap_rcv(sk, skb);
702 if (ret <= 0) {
703 __UDP_INC_STATS(sock_net(sk),
704 UDP_MIB_INDATAGRAMS,
705 is_udplite);
706 return -ret;
707 }
708 }
709
710 /* FALLTHROUGH -- it's a UDP Packet */
711 }
712
713 /*
714 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
715 */
716 if ((up->pcflag & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
717
718 if (up->pcrlen == 0) { /* full coverage was set */
719 net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n",
720 UDP_SKB_CB(skb)->cscov, skb->len);
721 goto drop;
722 }
723 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
724 net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n",
725 UDP_SKB_CB(skb)->cscov, up->pcrlen);
726 goto drop;
727 }
728 }
729
730 prefetch(&sk->sk_rmem_alloc);
731 if (rcu_access_pointer(sk->sk_filter) &&
732 udp_lib_checksum_complete(skb))
733 goto csum_error;
734
735 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
736 goto drop;
737
738 udp_csum_pull_header(skb);
739
740 skb_dst_drop(skb);
741
742 return __udpv6_queue_rcv_skb(sk, skb);
743
744 csum_error:
745 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
746 drop:
747 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
748 atomic_inc(&sk->sk_drops);
749 kfree_skb(skb);
750 return -1;
751 }
752
753 static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
754 {
755 struct sk_buff *next, *segs;
756 int ret;
757
758 if (likely(!udp_unexpected_gso(sk, skb)))
759 return udpv6_queue_rcv_one_skb(sk, skb);
760
761 __skb_push(skb, -skb_mac_offset(skb));
762 segs = udp_rcv_segment(sk, skb, false);
763 skb_list_walk_safe(segs, skb, next) {
764 __skb_pull(skb, skb_transport_offset(skb));
765
766 udp_post_segment_fix_csum(skb);
767 ret = udpv6_queue_rcv_one_skb(sk, skb);
768 if (ret > 0)
769 ip6_protocol_deliver_rcu(dev_net(skb->dev), skb, ret,
770 true);
771 }
772 return 0;
773 }
774
775 static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk,
776 __be16 loc_port, const struct in6_addr *loc_addr,
777 __be16 rmt_port, const struct in6_addr *rmt_addr,
778 int dif, int sdif, unsigned short hnum)
779 {
780 struct inet_sock *inet = inet_sk(sk);
781
782 if (!net_eq(sock_net(sk), net))
783 return false;
784
785 if (udp_sk(sk)->udp_port_hash != hnum ||
786 sk->sk_family != PF_INET6 ||
787 (inet->inet_dport && inet->inet_dport != rmt_port) ||
788 (!ipv6_addr_any(&sk->sk_v6_daddr) &&
789 !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) ||
790 !udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif) ||
791 (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
792 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr)))
793 return false;
794 if (!inet6_mc_check(sk, loc_addr, rmt_addr))
795 return false;
796 return true;
797 }
798
799 static void udp6_csum_zero_error(struct sk_buff *skb)
800 {
801 /* RFC 2460 section 8.1 says that we SHOULD log
802 * this error. Well, it is reasonable.
803 */
804 net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n",
805 &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source),
806 &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest));
807 }
808
809 /*
810 * Note: called only from the BH handler context,
811 * so we don't need to lock the hashes.
812 */
813 static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
814 const struct in6_addr *saddr, const struct in6_addr *daddr,
815 struct udp_table *udptable, int proto)
816 {
817 struct sock *sk, *first = NULL;
818 const struct udphdr *uh = udp_hdr(skb);
819 unsigned short hnum = ntohs(uh->dest);
820 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
821 unsigned int offset = offsetof(typeof(*sk), sk_node);
822 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
823 int dif = inet6_iif(skb);
824 int sdif = inet6_sdif(skb);
825 struct hlist_node *node;
826 struct sk_buff *nskb;
827
828 if (use_hash2) {
829 hash2_any = ipv6_portaddr_hash(net, &in6addr_any, hnum) &
830 udptable->mask;
831 hash2 = ipv6_portaddr_hash(net, daddr, hnum) & udptable->mask;
832 start_lookup:
833 hslot = &udptable->hash2[hash2];
834 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
835 }
836
837 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
838 if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr,
839 uh->source, saddr, dif, sdif,
840 hnum))
841 continue;
842 /* If zero checksum and no_check is not on for
843 * the socket then skip it.
844 */
845 if (!uh->check && !udp_sk(sk)->no_check6_rx)
846 continue;
847 if (!first) {
848 first = sk;
849 continue;
850 }
851 nskb = skb_clone(skb, GFP_ATOMIC);
852 if (unlikely(!nskb)) {
853 atomic_inc(&sk->sk_drops);
854 __UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
855 IS_UDPLITE(sk));
856 __UDP6_INC_STATS(net, UDP_MIB_INERRORS,
857 IS_UDPLITE(sk));
858 continue;
859 }
860
861 if (udpv6_queue_rcv_skb(sk, nskb) > 0)
862 consume_skb(nskb);
863 }
864
865 /* Also lookup *:port if we are using hash2 and haven't done so yet. */
866 if (use_hash2 && hash2 != hash2_any) {
867 hash2 = hash2_any;
868 goto start_lookup;
869 }
870
871 if (first) {
872 if (udpv6_queue_rcv_skb(first, skb) > 0)
873 consume_skb(skb);
874 } else {
875 kfree_skb(skb);
876 __UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
877 proto == IPPROTO_UDPLITE);
878 }
879 return 0;
880 }
881
882 static void udp6_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
883 {
884 if (udp_sk_rx_dst_set(sk, dst)) {
885 const struct rt6_info *rt = (const struct rt6_info *)dst;
886
887 inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
888 }
889 }
890
891 /* wrapper for udp_queue_rcv_skb tacking care of csum conversion and
892 * return code conversion for ip layer consumption
893 */
894 static int udp6_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
895 struct udphdr *uh)
896 {
897 int ret;
898
899 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
900 skb_checksum_try_convert(skb, IPPROTO_UDP, ip6_compute_pseudo);
901
902 ret = udpv6_queue_rcv_skb(sk, skb);
903
904 /* a return value > 0 means to resubmit the input */
905 if (ret > 0)
906 return ret;
907 return 0;
908 }
909
910 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
911 int proto)
912 {
913 const struct in6_addr *saddr, *daddr;
914 struct net *net = dev_net(skb->dev);
915 struct udphdr *uh;
916 struct sock *sk;
917 bool refcounted;
918 u32 ulen = 0;
919
920 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
921 goto discard;
922
923 saddr = &ipv6_hdr(skb)->saddr;
924 daddr = &ipv6_hdr(skb)->daddr;
925 uh = udp_hdr(skb);
926
927 ulen = ntohs(uh->len);
928 if (ulen > skb->len)
929 goto short_packet;
930
931 if (proto == IPPROTO_UDP) {
932 /* UDP validates ulen. */
933
934 /* Check for jumbo payload */
935 if (ulen == 0)
936 ulen = skb->len;
937
938 if (ulen < sizeof(*uh))
939 goto short_packet;
940
941 if (ulen < skb->len) {
942 if (pskb_trim_rcsum(skb, ulen))
943 goto short_packet;
944 saddr = &ipv6_hdr(skb)->saddr;
945 daddr = &ipv6_hdr(skb)->daddr;
946 uh = udp_hdr(skb);
947 }
948 }
949
950 if (udp6_csum_init(skb, uh, proto))
951 goto csum_error;
952
953 /* Check if the socket is already available, e.g. due to early demux */
954 sk = skb_steal_sock(skb, &refcounted);
955 if (sk) {
956 struct dst_entry *dst = skb_dst(skb);
957 int ret;
958
959 if (unlikely(sk->sk_rx_dst != dst))
960 udp6_sk_rx_dst_set(sk, dst);
961
962 if (!uh->check && !udp_sk(sk)->no_check6_rx) {
963 if (refcounted)
964 sock_put(sk);
965 goto report_csum_error;
966 }
967
968 ret = udp6_unicast_rcv_skb(sk, skb, uh);
969 if (refcounted)
970 sock_put(sk);
971 return ret;
972 }
973
974 /*
975 * Multicast receive code
976 */
977 if (ipv6_addr_is_multicast(daddr))
978 return __udp6_lib_mcast_deliver(net, skb,
979 saddr, daddr, udptable, proto);
980
981 /* Unicast */
982 sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
983 if (sk) {
984 if (!uh->check && !udp_sk(sk)->no_check6_rx)
985 goto report_csum_error;
986 return udp6_unicast_rcv_skb(sk, skb, uh);
987 }
988
989 if (!uh->check)
990 goto report_csum_error;
991
992 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
993 goto discard;
994
995 if (udp_lib_checksum_complete(skb))
996 goto csum_error;
997
998 __UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
999 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
1000
1001 kfree_skb(skb);
1002 return 0;
1003
1004 short_packet:
1005 net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
1006 proto == IPPROTO_UDPLITE ? "-Lite" : "",
1007 saddr, ntohs(uh->source),
1008 ulen, skb->len,
1009 daddr, ntohs(uh->dest));
1010 goto discard;
1011
1012 report_csum_error:
1013 udp6_csum_zero_error(skb);
1014 csum_error:
1015 __UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
1016 discard:
1017 __UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1018 kfree_skb(skb);
1019 return 0;
1020 }
1021
1022
1023 static struct sock *__udp6_lib_demux_lookup(struct net *net,
1024 __be16 loc_port, const struct in6_addr *loc_addr,
1025 __be16 rmt_port, const struct in6_addr *rmt_addr,
1026 int dif, int sdif)
1027 {
1028 unsigned short hnum = ntohs(loc_port);
1029 unsigned int hash2 = ipv6_portaddr_hash(net, loc_addr, hnum);
1030 unsigned int slot2 = hash2 & udp_table.mask;
1031 struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
1032 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
1033 struct sock *sk;
1034
1035 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
1036 if (sk->sk_state == TCP_ESTABLISHED &&
1037 INET6_MATCH(sk, net, rmt_addr, loc_addr, ports, dif, sdif))
1038 return sk;
1039 /* Only check first socket in chain */
1040 break;
1041 }
1042 return NULL;
1043 }
1044
1045 INDIRECT_CALLABLE_SCOPE void udp_v6_early_demux(struct sk_buff *skb)
1046 {
1047 struct net *net = dev_net(skb->dev);
1048 const struct udphdr *uh;
1049 struct sock *sk;
1050 struct dst_entry *dst;
1051 int dif = skb->dev->ifindex;
1052 int sdif = inet6_sdif(skb);
1053
1054 if (!pskb_may_pull(skb, skb_transport_offset(skb) +
1055 sizeof(struct udphdr)))
1056 return;
1057
1058 uh = udp_hdr(skb);
1059
1060 if (skb->pkt_type == PACKET_HOST)
1061 sk = __udp6_lib_demux_lookup(net, uh->dest,
1062 &ipv6_hdr(skb)->daddr,
1063 uh->source, &ipv6_hdr(skb)->saddr,
1064 dif, sdif);
1065 else
1066 return;
1067
1068 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
1069 return;
1070
1071 skb->sk = sk;
1072 skb->destructor = sock_efree;
1073 dst = READ_ONCE(sk->sk_rx_dst);
1074
1075 if (dst)
1076 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1077 if (dst) {
1078 /* set noref for now.
1079 * any place which wants to hold dst has to call
1080 * dst_hold_safe()
1081 */
1082 skb_dst_set_noref(skb, dst);
1083 }
1084 }
1085
1086 INDIRECT_CALLABLE_SCOPE int udpv6_rcv(struct sk_buff *skb)
1087 {
1088 return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1089 }
1090
1091 /*
1092 * Throw away all pending data and cancel the corking. Socket is locked.
1093 */
1094 static void udp_v6_flush_pending_frames(struct sock *sk)
1095 {
1096 struct udp_sock *up = udp_sk(sk);
1097
1098 if (up->pending == AF_INET)
1099 udp_flush_pending_frames(sk);
1100 else if (up->pending) {
1101 up->len = 0;
1102 up->pending = 0;
1103 ip6_flush_pending_frames(sk);
1104 }
1105 }
1106
1107 static int udpv6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
1108 int addr_len)
1109 {
1110 if (addr_len < offsetofend(struct sockaddr, sa_family))
1111 return -EINVAL;
1112 /* The following checks are replicated from __ip6_datagram_connect()
1113 * and intended to prevent BPF program called below from accessing
1114 * bytes that are out of the bound specified by user in addr_len.
1115 */
1116 if (uaddr->sa_family == AF_INET) {
1117 if (__ipv6_only_sock(sk))
1118 return -EAFNOSUPPORT;
1119 return udp_pre_connect(sk, uaddr, addr_len);
1120 }
1121
1122 if (addr_len < SIN6_LEN_RFC2133)
1123 return -EINVAL;
1124
1125 return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr);
1126 }
1127
1128 /**
1129 * udp6_hwcsum_outgoing - handle outgoing HW checksumming
1130 * @sk: socket we are sending on
1131 * @skb: sk_buff containing the filled-in UDP header
1132 * (checksum field must be zeroed out)
1133 * @saddr: source address
1134 * @daddr: destination address
1135 * @len: length of packet
1136 */
1137 static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
1138 const struct in6_addr *saddr,
1139 const struct in6_addr *daddr, int len)
1140 {
1141 unsigned int offset;
1142 struct udphdr *uh = udp_hdr(skb);
1143 struct sk_buff *frags = skb_shinfo(skb)->frag_list;
1144 __wsum csum = 0;
1145
1146 if (!frags) {
1147 /* Only one fragment on the socket. */
1148 skb->csum_start = skb_transport_header(skb) - skb->head;
1149 skb->csum_offset = offsetof(struct udphdr, check);
1150 uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
1151 } else {
1152 /*
1153 * HW-checksum won't work as there are two or more
1154 * fragments on the socket so that all csums of sk_buffs
1155 * should be together
1156 */
1157 offset = skb_transport_offset(skb);
1158 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
1159 csum = skb->csum;
1160
1161 skb->ip_summed = CHECKSUM_NONE;
1162
1163 do {
1164 csum = csum_add(csum, frags->csum);
1165 } while ((frags = frags->next));
1166
1167 uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
1168 csum);
1169 if (uh->check == 0)
1170 uh->check = CSUM_MANGLED_0;
1171 }
1172 }
1173
1174 /*
1175 * Sending
1176 */
1177
1178 static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6,
1179 struct inet_cork *cork)
1180 {
1181 struct sock *sk = skb->sk;
1182 struct udphdr *uh;
1183 int err = 0;
1184 int is_udplite = IS_UDPLITE(sk);
1185 __wsum csum = 0;
1186 int offset = skb_transport_offset(skb);
1187 int len = skb->len - offset;
1188 int datalen = len - sizeof(*uh);
1189
1190 /*
1191 * Create a UDP header
1192 */
1193 uh = udp_hdr(skb);
1194 uh->source = fl6->fl6_sport;
1195 uh->dest = fl6->fl6_dport;
1196 uh->len = htons(len);
1197 uh->check = 0;
1198
1199 if (cork->gso_size) {
1200 const int hlen = skb_network_header_len(skb) +
1201 sizeof(struct udphdr);
1202
1203 if (hlen + cork->gso_size > cork->fragsize) {
1204 kfree_skb(skb);
1205 return -EINVAL;
1206 }
1207 if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS) {
1208 kfree_skb(skb);
1209 return -EINVAL;
1210 }
1211 if (udp_sk(sk)->no_check6_tx) {
1212 kfree_skb(skb);
1213 return -EINVAL;
1214 }
1215 if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite ||
1216 dst_xfrm(skb_dst(skb))) {
1217 kfree_skb(skb);
1218 return -EIO;
1219 }
1220
1221 if (datalen > cork->gso_size) {
1222 skb_shinfo(skb)->gso_size = cork->gso_size;
1223 skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
1224 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen,
1225 cork->gso_size);
1226 }
1227 goto csum_partial;
1228 }
1229
1230 if (is_udplite)
1231 csum = udplite_csum(skb);
1232 else if (udp_sk(sk)->no_check6_tx) { /* UDP csum disabled */
1233 skb->ip_summed = CHECKSUM_NONE;
1234 goto send;
1235 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
1236 csum_partial:
1237 udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len);
1238 goto send;
1239 } else
1240 csum = udp_csum(skb);
1241
1242 /* add protocol-dependent pseudo-header */
1243 uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
1244 len, fl6->flowi6_proto, csum);
1245 if (uh->check == 0)
1246 uh->check = CSUM_MANGLED_0;
1247
1248 send:
1249 err = ip6_send_skb(skb);
1250 if (err) {
1251 if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
1252 UDP6_INC_STATS(sock_net(sk),
1253 UDP_MIB_SNDBUFERRORS, is_udplite);
1254 err = 0;
1255 }
1256 } else {
1257 UDP6_INC_STATS(sock_net(sk),
1258 UDP_MIB_OUTDATAGRAMS, is_udplite);
1259 }
1260 return err;
1261 }
1262
1263 static int udp_v6_push_pending_frames(struct sock *sk)
1264 {
1265 struct sk_buff *skb;
1266 struct udp_sock *up = udp_sk(sk);
1267 struct flowi6 fl6;
1268 int err = 0;
1269
1270 if (up->pending == AF_INET)
1271 return udp_push_pending_frames(sk);
1272
1273 /* ip6_finish_skb will release the cork, so make a copy of
1274 * fl6 here.
1275 */
1276 fl6 = inet_sk(sk)->cork.fl.u.ip6;
1277
1278 skb = ip6_finish_skb(sk);
1279 if (!skb)
1280 goto out;
1281
1282 err = udp_v6_send_skb(skb, &fl6, &inet_sk(sk)->cork.base);
1283
1284 out:
1285 up->len = 0;
1286 up->pending = 0;
1287 return err;
1288 }
1289
1290 int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1291 {
1292 struct ipv6_txoptions opt_space;
1293 struct udp_sock *up = udp_sk(sk);
1294 struct inet_sock *inet = inet_sk(sk);
1295 struct ipv6_pinfo *np = inet6_sk(sk);
1296 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
1297 struct in6_addr *daddr, *final_p, final;
1298 struct ipv6_txoptions *opt = NULL;
1299 struct ipv6_txoptions *opt_to_free = NULL;
1300 struct ip6_flowlabel *flowlabel = NULL;
1301 struct flowi6 fl6;
1302 struct dst_entry *dst;
1303 struct ipcm6_cookie ipc6;
1304 int addr_len = msg->msg_namelen;
1305 bool connected = false;
1306 int ulen = len;
1307 int corkreq = READ_ONCE(up->corkflag) || msg->msg_flags&MSG_MORE;
1308 int err;
1309 int is_udplite = IS_UDPLITE(sk);
1310 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1311
1312 ipcm6_init(&ipc6);
1313 ipc6.gso_size = READ_ONCE(up->gso_size);
1314 ipc6.sockc.tsflags = sk->sk_tsflags;
1315 ipc6.sockc.mark = sk->sk_mark;
1316
1317 /* destination address check */
1318 if (sin6) {
1319 if (addr_len < offsetof(struct sockaddr, sa_data))
1320 return -EINVAL;
1321
1322 switch (sin6->sin6_family) {
1323 case AF_INET6:
1324 if (addr_len < SIN6_LEN_RFC2133)
1325 return -EINVAL;
1326 daddr = &sin6->sin6_addr;
1327 if (ipv6_addr_any(daddr) &&
1328 ipv6_addr_v4mapped(&np->saddr))
1329 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
1330 daddr);
1331 break;
1332 case AF_INET:
1333 goto do_udp_sendmsg;
1334 case AF_UNSPEC:
1335 msg->msg_name = sin6 = NULL;
1336 msg->msg_namelen = addr_len = 0;
1337 daddr = NULL;
1338 break;
1339 default:
1340 return -EINVAL;
1341 }
1342 } else if (!up->pending) {
1343 if (sk->sk_state != TCP_ESTABLISHED)
1344 return -EDESTADDRREQ;
1345 daddr = &sk->sk_v6_daddr;
1346 } else
1347 daddr = NULL;
1348
1349 if (daddr) {
1350 if (ipv6_addr_v4mapped(daddr)) {
1351 struct sockaddr_in sin;
1352 sin.sin_family = AF_INET;
1353 sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
1354 sin.sin_addr.s_addr = daddr->s6_addr32[3];
1355 msg->msg_name = &sin;
1356 msg->msg_namelen = sizeof(sin);
1357 do_udp_sendmsg:
1358 if (__ipv6_only_sock(sk))
1359 return -ENETUNREACH;
1360 return udp_sendmsg(sk, msg, len);
1361 }
1362 }
1363
1364 if (up->pending == AF_INET)
1365 return udp_sendmsg(sk, msg, len);
1366
1367 /* Rough check on arithmetic overflow,
1368 better check is made in ip6_append_data().
1369 */
1370 if (len > INT_MAX - sizeof(struct udphdr))
1371 return -EMSGSIZE;
1372
1373 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
1374 if (up->pending) {
1375 /*
1376 * There are pending frames.
1377 * The socket lock must be held while it's corked.
1378 */
1379 lock_sock(sk);
1380 if (likely(up->pending)) {
1381 if (unlikely(up->pending != AF_INET6)) {
1382 release_sock(sk);
1383 return -EAFNOSUPPORT;
1384 }
1385 dst = NULL;
1386 goto do_append_data;
1387 }
1388 release_sock(sk);
1389 }
1390 ulen += sizeof(struct udphdr);
1391
1392 memset(&fl6, 0, sizeof(fl6));
1393
1394 if (sin6) {
1395 if (sin6->sin6_port == 0)
1396 return -EINVAL;
1397
1398 fl6.fl6_dport = sin6->sin6_port;
1399 daddr = &sin6->sin6_addr;
1400
1401 if (np->sndflow) {
1402 fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1403 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
1404 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1405 if (IS_ERR(flowlabel))
1406 return -EINVAL;
1407 }
1408 }
1409
1410 /*
1411 * Otherwise it will be difficult to maintain
1412 * sk->sk_dst_cache.
1413 */
1414 if (sk->sk_state == TCP_ESTABLISHED &&
1415 ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
1416 daddr = &sk->sk_v6_daddr;
1417
1418 if (addr_len >= sizeof(struct sockaddr_in6) &&
1419 sin6->sin6_scope_id &&
1420 __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
1421 fl6.flowi6_oif = sin6->sin6_scope_id;
1422 } else {
1423 if (sk->sk_state != TCP_ESTABLISHED)
1424 return -EDESTADDRREQ;
1425
1426 fl6.fl6_dport = inet->inet_dport;
1427 daddr = &sk->sk_v6_daddr;
1428 fl6.flowlabel = np->flow_label;
1429 connected = true;
1430 }
1431
1432 if (!fl6.flowi6_oif)
1433 fl6.flowi6_oif = sk->sk_bound_dev_if;
1434
1435 if (!fl6.flowi6_oif)
1436 fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
1437
1438 fl6.flowi6_mark = ipc6.sockc.mark;
1439 fl6.flowi6_uid = sk->sk_uid;
1440
1441 if (msg->msg_controllen) {
1442 opt = &opt_space;
1443 memset(opt, 0, sizeof(struct ipv6_txoptions));
1444 opt->tot_len = sizeof(*opt);
1445 ipc6.opt = opt;
1446
1447 err = udp_cmsg_send(sk, msg, &ipc6.gso_size);
1448 if (err > 0)
1449 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6,
1450 &ipc6);
1451 if (err < 0) {
1452 fl6_sock_release(flowlabel);
1453 return err;
1454 }
1455 if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
1456 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1457 if (IS_ERR(flowlabel))
1458 return -EINVAL;
1459 }
1460 if (!(opt->opt_nflen|opt->opt_flen))
1461 opt = NULL;
1462 connected = false;
1463 }
1464 if (!opt) {
1465 opt = txopt_get(np);
1466 opt_to_free = opt;
1467 }
1468 if (flowlabel)
1469 opt = fl6_merge_options(&opt_space, flowlabel, opt);
1470 opt = ipv6_fixup_options(&opt_space, opt);
1471 ipc6.opt = opt;
1472
1473 fl6.flowi6_proto = sk->sk_protocol;
1474 fl6.daddr = *daddr;
1475 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
1476 fl6.saddr = np->saddr;
1477 fl6.fl6_sport = inet->inet_sport;
1478
1479 if (cgroup_bpf_enabled(CGROUP_UDP6_SENDMSG) && !connected) {
1480 err = BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk,
1481 (struct sockaddr *)sin6, &fl6.saddr);
1482 if (err)
1483 goto out_no_dst;
1484 if (sin6) {
1485 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
1486 /* BPF program rewrote IPv6-only by IPv4-mapped
1487 * IPv6. It's currently unsupported.
1488 */
1489 err = -ENOTSUPP;
1490 goto out_no_dst;
1491 }
1492 if (sin6->sin6_port == 0) {
1493 /* BPF program set invalid port. Reject it. */
1494 err = -EINVAL;
1495 goto out_no_dst;
1496 }
1497 fl6.fl6_dport = sin6->sin6_port;
1498 fl6.daddr = sin6->sin6_addr;
1499 }
1500 }
1501
1502 if (ipv6_addr_any(&fl6.daddr))
1503 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1504
1505 final_p = fl6_update_dst(&fl6, opt, &final);
1506 if (final_p)
1507 connected = false;
1508
1509 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) {
1510 fl6.flowi6_oif = np->mcast_oif;
1511 connected = false;
1512 } else if (!fl6.flowi6_oif)
1513 fl6.flowi6_oif = np->ucast_oif;
1514
1515 security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
1516
1517 if (ipc6.tclass < 0)
1518 ipc6.tclass = np->tclass;
1519
1520 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
1521
1522 dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p, connected);
1523 if (IS_ERR(dst)) {
1524 err = PTR_ERR(dst);
1525 dst = NULL;
1526 goto out;
1527 }
1528
1529 if (ipc6.hlimit < 0)
1530 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
1531
1532 if (msg->msg_flags&MSG_CONFIRM)
1533 goto do_confirm;
1534 back_from_confirm:
1535
1536 /* Lockless fast path for the non-corking case */
1537 if (!corkreq) {
1538 struct inet_cork_full cork;
1539 struct sk_buff *skb;
1540
1541 skb = ip6_make_skb(sk, getfrag, msg, ulen,
1542 sizeof(struct udphdr), &ipc6,
1543 &fl6, (struct rt6_info *)dst,
1544 msg->msg_flags, &cork);
1545 err = PTR_ERR(skb);
1546 if (!IS_ERR_OR_NULL(skb))
1547 err = udp_v6_send_skb(skb, &fl6, &cork.base);
1548 goto out;
1549 }
1550
1551 lock_sock(sk);
1552 if (unlikely(up->pending)) {
1553 /* The socket is already corked while preparing it. */
1554 /* ... which is an evident application bug. --ANK */
1555 release_sock(sk);
1556
1557 net_dbg_ratelimited("udp cork app bug 2\n");
1558 err = -EINVAL;
1559 goto out;
1560 }
1561
1562 up->pending = AF_INET6;
1563
1564 do_append_data:
1565 if (ipc6.dontfrag < 0)
1566 ipc6.dontfrag = np->dontfrag;
1567 up->len += ulen;
1568 err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr),
1569 &ipc6, &fl6, (struct rt6_info *)dst,
1570 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1571 if (err)
1572 udp_v6_flush_pending_frames(sk);
1573 else if (!corkreq)
1574 err = udp_v6_push_pending_frames(sk);
1575 else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1576 up->pending = 0;
1577
1578 if (err > 0)
1579 err = np->recverr ? net_xmit_errno(err) : 0;
1580 release_sock(sk);
1581
1582 out:
1583 dst_release(dst);
1584 out_no_dst:
1585 fl6_sock_release(flowlabel);
1586 txopt_put(opt_to_free);
1587 if (!err)
1588 return len;
1589 /*
1590 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1591 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1592 * we don't have a good statistic (IpOutDiscards but it can be too many
1593 * things). We could add another new stat but at least for now that
1594 * seems like overkill.
1595 */
1596 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1597 UDP6_INC_STATS(sock_net(sk),
1598 UDP_MIB_SNDBUFERRORS, is_udplite);
1599 }
1600 return err;
1601
1602 do_confirm:
1603 if (msg->msg_flags & MSG_PROBE)
1604 dst_confirm_neigh(dst, &fl6.daddr);
1605 if (!(msg->msg_flags&MSG_PROBE) || len)
1606 goto back_from_confirm;
1607 err = 0;
1608 goto out;
1609 }
1610
1611 void udpv6_destroy_sock(struct sock *sk)
1612 {
1613 struct udp_sock *up = udp_sk(sk);
1614 lock_sock(sk);
1615
1616 /* protects from races with udp_abort() */
1617 sock_set_flag(sk, SOCK_DEAD);
1618 udp_v6_flush_pending_frames(sk);
1619 release_sock(sk);
1620
1621 if (static_branch_unlikely(&udpv6_encap_needed_key)) {
1622 if (up->encap_type) {
1623 void (*encap_destroy)(struct sock *sk);
1624 encap_destroy = READ_ONCE(up->encap_destroy);
1625 if (encap_destroy)
1626 encap_destroy(sk);
1627 }
1628 if (up->encap_enabled) {
1629 static_branch_dec(&udpv6_encap_needed_key);
1630 udp_encap_disable();
1631 }
1632 }
1633
1634 inet6_destroy_sock(sk);
1635 }
1636
1637 /*
1638 * Socket option code for UDP
1639 */
1640 int udpv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
1641 unsigned int optlen)
1642 {
1643 if (level == SOL_UDP || level == SOL_UDPLITE)
1644 return udp_lib_setsockopt(sk, level, optname,
1645 optval, optlen,
1646 udp_v6_push_pending_frames);
1647 return ipv6_setsockopt(sk, level, optname, optval, optlen);
1648 }
1649
1650 int udpv6_getsockopt(struct sock *sk, int level, int optname,
1651 char __user *optval, int __user *optlen)
1652 {
1653 if (level == SOL_UDP || level == SOL_UDPLITE)
1654 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1655 return ipv6_getsockopt(sk, level, optname, optval, optlen);
1656 }
1657
1658 /* thinking of making this const? Don't.
1659 * early_demux can change based on sysctl.
1660 */
1661 static struct inet6_protocol udpv6_protocol = {
1662 .early_demux = udp_v6_early_demux,
1663 .early_demux_handler = udp_v6_early_demux,
1664 .handler = udpv6_rcv,
1665 .err_handler = udpv6_err,
1666 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1667 };
1668
1669 /* ------------------------------------------------------------------------ */
1670 #ifdef CONFIG_PROC_FS
1671 int udp6_seq_show(struct seq_file *seq, void *v)
1672 {
1673 if (v == SEQ_START_TOKEN) {
1674 seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
1675 } else {
1676 int bucket = ((struct udp_iter_state *)seq->private)->bucket;
1677 struct inet_sock *inet = inet_sk(v);
1678 __u16 srcp = ntohs(inet->inet_sport);
1679 __u16 destp = ntohs(inet->inet_dport);
1680 __ip6_dgram_sock_seq_show(seq, v, srcp, destp,
1681 udp_rqueue_get(v), bucket);
1682 }
1683 return 0;
1684 }
1685
1686 const struct seq_operations udp6_seq_ops = {
1687 .start = udp_seq_start,
1688 .next = udp_seq_next,
1689 .stop = udp_seq_stop,
1690 .show = udp6_seq_show,
1691 };
1692 EXPORT_SYMBOL(udp6_seq_ops);
1693
1694 static struct udp_seq_afinfo udp6_seq_afinfo = {
1695 .family = AF_INET6,
1696 .udp_table = &udp_table,
1697 };
1698
1699 int __net_init udp6_proc_init(struct net *net)
1700 {
1701 if (!proc_create_net_data("udp6", 0444, net->proc_net, &udp6_seq_ops,
1702 sizeof(struct udp_iter_state), &udp6_seq_afinfo))
1703 return -ENOMEM;
1704 return 0;
1705 }
1706
1707 void udp6_proc_exit(struct net *net)
1708 {
1709 remove_proc_entry("udp6", net->proc_net);
1710 }
1711 #endif /* CONFIG_PROC_FS */
1712
1713 /* ------------------------------------------------------------------------ */
1714
1715 struct proto udpv6_prot = {
1716 .name = "UDPv6",
1717 .owner = THIS_MODULE,
1718 .close = udp_lib_close,
1719 .pre_connect = udpv6_pre_connect,
1720 .connect = ip6_datagram_connect,
1721 .disconnect = udp_disconnect,
1722 .ioctl = udp_ioctl,
1723 .init = udp_init_sock,
1724 .destroy = udpv6_destroy_sock,
1725 .setsockopt = udpv6_setsockopt,
1726 .getsockopt = udpv6_getsockopt,
1727 .sendmsg = udpv6_sendmsg,
1728 .recvmsg = udpv6_recvmsg,
1729 .release_cb = ip6_datagram_release_cb,
1730 .hash = udp_lib_hash,
1731 .unhash = udp_lib_unhash,
1732 .rehash = udp_v6_rehash,
1733 .get_port = udp_v6_get_port,
1734 #ifdef CONFIG_BPF_SYSCALL
1735 .psock_update_sk_prot = udp_bpf_update_proto,
1736 #endif
1737 .memory_allocated = &udp_memory_allocated,
1738 .sysctl_mem = sysctl_udp_mem,
1739 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
1740 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
1741 .obj_size = sizeof(struct udp6_sock),
1742 .h.udp_table = &udp_table,
1743 .diag_destroy = udp_abort,
1744 };
1745
1746 static struct inet_protosw udpv6_protosw = {
1747 .type = SOCK_DGRAM,
1748 .protocol = IPPROTO_UDP,
1749 .prot = &udpv6_prot,
1750 .ops = &inet6_dgram_ops,
1751 .flags = INET_PROTOSW_PERMANENT,
1752 };
1753
1754 int __init udpv6_init(void)
1755 {
1756 int ret;
1757
1758 ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1759 if (ret)
1760 goto out;
1761
1762 ret = inet6_register_protosw(&udpv6_protosw);
1763 if (ret)
1764 goto out_udpv6_protocol;
1765 out:
1766 return ret;
1767
1768 out_udpv6_protocol:
1769 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1770 goto out;
1771 }
1772
1773 void udpv6_exit(void)
1774 {
1775 inet6_unregister_protosw(&udpv6_protosw);
1776 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1777 }
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